This invention relates to furnace charges for recycling metal and a method for making such charges, especially from scrap metal, and, more particularly, to a product and method for forming compact, dense, economical, metal furnace charging pellets especially for reusing scrap metals.
The recycling of scrap metals has become increasingly important due to the dwindling supply of natural resources. A prolific source of recyclable metal is provided by various industries which produce turnings, borings, punchings, chips, chunks and other small pieces of metal of various types as by-products of manufacturing processes. However, problems arise in the collection, handling and use of such small scrap metal pieces.
For metals such as iron and steel, it is necessary to blend scrap metal with quantities of virgin ore and other materials in melting furnaces. Such blending requires the charging of furnaces with predetermined quantities of scrap metal. Such charging requires the provision of scrap in a form which can be easily loaded into melting furnaces, which hold together to provide little or no spillage or loss of metal in transportation, storage, handling or loading, and yet is of sufficient nature to blend and mix well in the furnace when loaded. Moreover, a primary concern in the entire effort of recycling scrap metal is to do so economically.
More specific problems occur in the reuse of small metal pieces such as the turnings, borings and punchings resulting from the manufacture of screws and other machined metal parts. The collection, storage, transportation and loading of such small metal pieces from such processes requires conversion of the pieces into larger masses for ease in handling and loading. Prior methods of such conversion include compaction of the scrap metal into briquets as well as the loading of such scrap into larger containers.
One drawback of briquets which are not encased in some type of container is the loss of scrap from such briquets during handling and loading. It has been proposed to fuse briquets to prevent such loss but such fusion requires complex processes as well as significantly greater amounts of energy usage which of course raises the cost of reusing the scrap. With respect to the encasement of scrap in containers, many methods have been proposed including insertion of scrap into tubular containers which then must be closed to prevent escape of the scrap. With many of such encasement methods, the irregular shape of the individual scrap pieces has required large container volume because of the air spaces between the metal pieces. This increases the costs of storage, transportation and loading because of insufficient density.
In addition, the closing of prior known containers once scrap has been inserted has been a costly and/or difficult previously known process. Many of such prior methods have also failed to adequately retain the metal within the containers. Also, such processes have typically utilized a certain amount of new materials further adding to the cost of recycling the scrap metal.
The present invention has been devised as an improved furnace charging product which overcomes the above problems as well as a method for economically manufacturing such furnace charges to enable recycling of metal pieces which otherwise could not be used.